This invention relates to a holder for a test strip and a method of using the holder. The test strip holder positions a test strip within a liquid to ensure that liquid contacts and moves up the test strip only by capillary action.
Conventional test strips are hand-held and immersed in the liquid. The test strip is then removed from the liquid and the results are determined from reading the test strip. In this "immersion" method, the tester is required to physically hold the test strip in the liquid. This can result in problems arising from contamination of the test strip from the tester's fingers, which may result in unreliable or tainted results.
Further problems may arise from prolonged contact of the test strip with the liquid to be tested. Some test strips require contact with a liquid for a predetermined time period. If the strip contacts the liquid for an extended period of time, the results may be faulty or unreliable.
Other known test strips require application of a specific volume to the test strip, for example a predetermined number of drops. Other test strips require immersion of the test strip in a liquid up to a prescribed height for a designated period of time. These types of test strips require extensive and exacting tester interface. The tester must maintain constant surveillance of the test strip and liquid to ensure proper test conditions. This is an inefficient use of the tester's time. Further, it can easily lead to errors in the testing.
Holders for test strips are known that include a test strip enclosed within a housing. However, this type of test strip holder also suffers from the above disadvantages, such as the need for continuous monitoring and careful measuring. The housing must be dipped into a liquid to a certain height for a predetermined time. The tester must hold the holder or cause the holder to be supported at the predetermined depth for the designated time period. If the test strip and housing are inserted beyond the depth and/or for more or less than the predetermined time, the results from the test may be inaccurate and unreliable.
Further, known test strip holder devices do not include any structure to assure that the liquid contacts the test strip only up to a certain predetermined height. Even if the housing is provided with a mark designating the insertion depth, the tester must manually hold the test strip holder in the liquid for a designated period of time. Further, depending on the clarity of the liquid and the container in which the liquid is held, it is difficult to accurately position the test strip holder with the mark positioned at the surface of the liquid.
Known test strip holders also do not ensure the positioning of the test strip away from the internal side walls of the holder. Therefore, the liquid may travel up the side walls of the test strip holder by capillary action and prematurely contact the test strip, rather than only travel up the test strip. Premature contact of the test strip with liquid may cause faulty and unreliable test results, especially if the test strip is provided with a plurality of test strip zones that are to be sequentially contacted. Moreover, direct and prolonged liquid contact with the strip may cause unreliable test results.